The present invention relates to an attaching structure for a valve device to be installed in a fuel tank, in particular, an attaching structure suitable for a plurality of valve devices to be installed in a fuel tank.
Various valve devices are attached to an upper portion of a fuel tank to be installed in a vehicle or the like for the purpose of, for example, discharging fuel vapor generated in the tank to the side of a canister, or preventing the fuel from leaking when a car body is inclined or fallen down. FIGS. 6 and 7 show attaching structures of the valve device as described above.
FIG. 6 shows an attaching structure of a valve device disclosed in Japanese Patent Publication (KOKAI) No. 07-35255. In the attaching structure, a valve device 50 includes an engagement portion 52 provided on an upper portion of a housing 51 and a connecting pipe portion 53 disposed on a sidewall of the housing 51. The valve device 50 is attached to an upper surface 61 of the tank 60 through a bracket 65. The bracket 65 is a substantially flat metal plate, and welded to the upper surface 61 of the tank. The bracket 65 constitutes an engagement portion 66 corresponding to the engagement portion 52. The valve device 50 is attached in a suspending state through engagement between the engaging portion 52 and the engagement portion 66. A connecting pipe portion 53 is connected to a pipe 70 communicating the inside of the tank with the outside thereof.
FIG. 7 shows an attaching structure of a valve device disclosed in Japanese Patent Publication (KOKAI) No. 11-321354. In the attaching structure, a valve device 55 includes a connecting pipe portion 57 with a large diameter disposed on an upper portion of a housing 56, and notch grooves 58 formed on both sides around the connecting pipe portion 57. The valve device 55 is attached to an upper surface 63 of a tank 62 through a bracket 67. The bracket 67 has a substantially L-shape. A vertical plate of the L-shape includes an opening for receiving the connecting pipe portion 57 and an engagement claw inserting inside through the notch groove 58. A horizontal plate of the L-character shape is fixed to an upper surface 63 in the tank.
The valve device 55 is attached to the opening of the vertical plate of the bracket 67 in a state that a corresponding end of a pipe 71 for communicating the outside and the inside of the tank is inserted into the connecting pipe portion 57. In this state, the engaging claw enters the connecting pipe portion 57 through the notch groove 58 to fix the corresponding end of the pipe 71 not to come off. As an attaching structure other than the above-mentioned structures, in a case that a fuel tank is made of a resin, the valve device may be directly welded to the upper portion of the tank.
In the conventional attaching structures for the valve devices as described above, each attaching structure is attached to the upper surface of the fuel tank through the bracket, or welded to the resin tank. Thus, there have been the following problems with respect to producing a tank. First, in the valve device, since the connecting pipe portion communicating with the outside is integrated with the housing, it is very difficult to change a position of the connecting pipe portion while the valve device is attached to the tank.
For this reason, in the installation work, it is difficult to accurately position the pipe (normally, the pipes 70, 71 are made of metal) in the tank. Further, it is not easy to remove the bracket, thereby deteriorating the workability. Also, the fuel tank for the vehicle has been designed in a more complicated shape according to an installation area in a car body or for increasing an effective capacity of the tank. Also, there has been a trend that the number of the valve devices has been increasing. Along with this trend, from a design point of view, it may be difficult to provide a tank with a large flat area for installing the valve device, or there are problems related to other functional components and their installation areas on the tank. Incidentally, in a case that the valve devices are welded or fused, when an abandoned fuel tank is scrapped, the separation work becomes a problem.
In view of the above defects, the present invention has been made, and an object of the invention is to provide an attaching structure for a valve device, wherein an attaching workability is improved, and, also a flexible installation is achieved.
Further objects and advantages of the invention will be apparent from the following description of the invention.